QuadraticTetra

VTKExamples/Cxx/GeometricObjects/QuadraticTetra


Description

The quadratic tetrahedron is a primary three-dimensional cell. It is defined by ten points. The first four points are located at the vertices of the tetrahedron; the next six are located in the middle of each of the six edges

Code

QuadraticTetra.cxx

#include <vtkActor.h>
#include <vtkDataSetMapper.h>
#include <vtkGlyph3D.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNamedColors.h>
#include <vtkPoints.h>
#include <vtkProperty.h>
#include <vtkQuadraticTetra.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkTessellatorFilter.h>
#include <vtkUnstructuredGrid.h>

namespace
{
vtkSmartPointer<vtkUnstructuredGrid> MakeQuadraticTetra();
}

int main (int, char *[])
{
  vtkSmartPointer<vtkNamedColors> namedColors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkSmartPointer<vtkUnstructuredGrid> uGrid =
    MakeQuadraticTetra();

  vtkSmartPointer<vtkTessellatorFilter> tessellate =
    vtkSmartPointer<vtkTessellatorFilter>::New();
  tessellate->SetInputData(uGrid);

  vtkSmartPointer<vtkDataSetMapper> mapper = 
    vtkSmartPointer<vtkDataSetMapper>::New();
  mapper->SetInputConnection(tessellate->GetOutputPort());
  mapper->ScalarVisibilityOff();

  // Create an actor for the grid
  vtkSmartPointer<vtkActor> actor = 
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->GetProperty()->SetDiffuseColor(
    namedColors->GetColor3d("Tomato").GetData());
  actor->GetProperty()->SetEdgeColor(
    namedColors->GetColor3d("IvoryBlack").GetData());
  actor->GetProperty()->EdgeVisibilityOn();

  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetRadius(0.02);

  vtkSmartPointer<vtkGlyph3D> glyph3D =
    vtkSmartPointer<vtkGlyph3D>::New();
  glyph3D->SetInputData(uGrid);
  glyph3D->SetSourceConnection(sphereSource->GetOutputPort());
  glyph3D->ScalingOff();
  glyph3D->Update();

  vtkSmartPointer<vtkDataSetMapper> glyph3DMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  glyph3DMapper->SetInputConnection(glyph3D->GetOutputPort());
  glyph3DMapper->ScalarVisibilityOff();

  vtkSmartPointer<vtkActor> glyph3DActor =
    vtkSmartPointer<vtkActor>::New();
  glyph3DActor->SetMapper(glyph3DMapper);
  glyph3DActor->GetProperty()->SetColor(
    namedColors->GetColor3d("Banana").GetData());

  // Visualize
  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetWindowName("Quadratic Tetra");
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  renderer->AddActor(actor);
  renderer->AddActor(glyph3DActor);
  renderer->SetBackground(namedColors->GetColor3d("SlateGray").GetData());

  renderWindow->Render();
  interactor->Start();

  return EXIT_SUCCESS;
}

namespace
{
vtkSmartPointer<vtkUnstructuredGrid> MakeQuadraticTetra()
{
  vtkSmartPointer<vtkQuadraticTetra> aTetra =
    vtkSmartPointer<vtkQuadraticTetra>::New();
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();

  double *pcoords = aTetra->GetParametricCoords();
  vtkSmartPointer<vtkMinimalStandardRandomSequence> rng =
    vtkSmartPointer<vtkMinimalStandardRandomSequence>::New();
  points->SetNumberOfPoints(aTetra->GetNumberOfPoints());
  rng->SetSeed(5070); // for testing
  for (auto i = 0; i < aTetra->GetNumberOfPoints(); ++i)
  {
    double perturbation[3];
    for (auto j = 0; j < 3; ++j)
    {
      rng->Next();
      perturbation[j] = rng->GetRangeValue(-0.1, 0.1);
    }
    aTetra->GetPointIds()->SetId(i, i);
    points->SetPoint(i,
                     *(pcoords + 3 * i) + perturbation[0],
                     *(pcoords + 3 * i + 1) + perturbation[1],
                     *(pcoords + 3 * i + 2) + perturbation[2]);
  }

  // Add the points and tetra to an unstructured grid
  vtkSmartPointer<vtkUnstructuredGrid> uGrid =
    vtkSmartPointer<vtkUnstructuredGrid>::New();
  uGrid->SetPoints(points);
  uGrid->InsertNextCell(aTetra->GetCellType(), aTetra->GetPointIds());

  return uGrid;
}
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(QuadraticTetra)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(QuadraticTetra MACOSX_BUNDLE QuadraticTetra.cxx )

target_link_libraries(QuadraticTetra ${VTK_LIBRARIES})

Download and Build QuadraticTetra

Click here to download QuadraticTetra and its CMakeLists.txt file. Once the tarball QuadraticTetra.tar has been downloaded and extracted,

cd QuadraticTetra/build 

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./QuadraticTetra

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.